Mucolytic salts,compositions and process for treating mucus

ABSTRACT

MUCOLYTIC COMPOSITIONS, ESPECIALLY EFFECTIVE FOR FLUIDIFYING MUCUS IN HUMANS, COMPRISING A MUCOLYTICALY EFFECTIVE AMOUNT OF A SALT AND/OR MIXTURE OF SALTS OF A MERCAPTO-ALKANE-SULFONIC ACID OF THE FORMULA HS-X-SO2H, WHEREIN X IS AN ALYLENE RADICAL HAVING 2-6 CARBON ATOMS AND AT LEAST ONE NON-TOXIC PHARMACEUTICALLY EFFECTIVE CARRIER.

United States Patent 3,567,835 MUCOLYTIC SALTS, COMPOSITIONS AND PROCESS FOR TREATING MUCUS Henri Morten, Forest, Belgium, assignor to UCB (Union Chimique Chemische Bedrijven), S.A., Saint-Gilles-les- Brussels, Belgium No Drawing. Original application May 2, 1966, Ser. No. 546,592. Divided and this application Dec. 13, 1968, Ser. No. 807,147 Claims priority, application Great Britain, May 7, 1965, 19,370/ 65 Int. Cl. A61u 27/00 US. Cl. 424-315 5 Claims ABSTRACT OF THE DISCLOSURE Mucolytic compositions, especially efiective for fluiditying mucus in humans, comprising a mucolytically effective amount of a salt and/0r mixture of salts of a mercapto-alkane-sulfonic acid of the formula HSXfiSO H, wherein X is an alkylene radical having 2-6 carbon atoms and at least one non-toxic pharmaceutically effective carrier.

This application is a division of Ser. No. 546,592, filed May 2, 1966, and now abandoned.

The present invention relates to therapeutic compounds having a mucolytic activity and to the process of their preparation. It relates also to therapeutic compositions containing said mucolytic compounds and to the process of their preparation. Furthermore, the invention relates to a mucolysis process wherein said mucolytic compounds and compositions are used.

According to the present invention, it has been found that the salts of mercaptoalkane-sulfonic acids constitute very active mucolytic agents having a very low toxicity. These salts can therefore be used whenever it is desired to fluidify mucus. Amongst the numerous possibilities of application of the fluidization of mucus, mention may be made of the mucolysis of secretions of the stomachal, intestinal, vaginal, etc. mucous membranes, the liquefaction of expectorations or pathological mucus with the view of their bacteriologic examination, the dissolution of all kinds of mucus during the cleaning of surgical instruments, and the like. But the application for which the mucolytic compounds suit best is the treatment of the respiratory tract diseases.

The accumulation of mucus in the respiratory tract considerably complicates the treatment of numerous diseases of the respiratory tract. The evacuation of this mucus is often difiicult and its presence has the effect of considerably reducing the action of medicines, such as vasoconstrictors, bronchodilators, anti-histaminics, antibiotics, anti-bacterials, anaesthetics, sedatives and the like.

Not only does the fluidisation of this mucus improve the activity of the products used in pathological conditions of the respiratory tract but, at the same time, it relieves the patient by permitting easier expectoration.

This mucus contains considerable quantities of mucoproteins. From the chemical point of view, these substances contain, in particular, disulfide bonds. It is well known that the breaking of these disulfide bridges by means of certain thiols in order to form new disulfides having a lower molecular weight, results in a considerable reduction of the viscosity of the mucus, thus facilitating its evacuation.

For this purpose, it has already been proposed to use mucolytic agents such as Z-mercaptoethanol, Z-mercaptoethylamine and cysteine, which compounds may be substituted, for example, on the amine nitrogen. However, the disadvantage of hitherto known mucolytics is their Patented Mar. 2, 1971 chemical instability. These compounds are, indeed, very sensitive to oxidation; in addition, they have a very disagreeable odour, which considerably restricts their medical use.

We have now found that the inorganic and organic salts of mercaptoalkane-sulfonic acids of the general formula HS-X-SO H, in which X represents a straight or branched alkylene radical containing from 2 to 6 carbon atoms, have a very high mucolytic activity, are practically odourless, have a low toxicity and possess an excellent storage stability.

Mercaptoalkane-sulfonic acids are, in fact, compounds which are already known and certain of their salts have already been proposed for use outside the medical field, such as the permanent waving of hair in cosmesis. As far as is known, however, it has not been shown that these compounds possess mucolytic properties.

Various forms of utilisation of the compounds according to the present invention are possible. Thus, it is possible to administer salts of mercaptoalkane-sulfonic acids with pharmaceutically-inactive inorganic or organic bases, if desired, mixed with suitable excipients. For example, sodium, ammonium or Z-amino-pyrimidine salts of 2- mercaptoethane-sulfonic acid may be used for this purpose.

A very advantageous method of utilisation consists in administering the compounds according to the present invention together with pharmaceutically-active compounds which are basic or not.

When these pharmaceutically-active compounds are not basic, they are mixed with the salts according to the present invention in the desired proportions in order to obtain simultaneously efficacious therapeutic and mucolytic activities.

When the pharmaceutically-active compounds are basic, the mercaptoalkane-sulfonic acids may be completely or partially neutralised with them.

If this neutralisation with the pharmaceutically-active basic compounds is only partial, it may be completed by the addition of pharmaceutically-inactive inorganic or organic bases. It is thus possible to vary, as desired, the ratio between the mucolytic agent and the medicine so that the salt thus obtained has, at the same time, the desired mucolytic and the desired pharmaceutical properties.

It is also possible for the mercaptoalkane-sulfonic acids to be completely neutralized with a pharmaceutically-active base when the respective activities of the acid and of the base so permit. However, if for a given medical application the' pharmaceutical activity of the base in the salt is too high as compared with that of the acid, an appropriate quantity of a salt of a mercaptoalkane-sulfonic acid and a pharmaceutically inactive base may be added and the obtained mixture used for the preparation of a medicine.

One very advantageous characteristic of the invention is the fact that the mercaptoalkane-sulfonic acids are capable of forming, with the inorganic and organic bases, stable, odourless salts which have clearly determined physical constants, particularly a sharp melting point. These bases include not only pharmaceutically-inactive bases, such as Z-aminopyridine, Z-aminopyrimidine, guanidine and the like, but also pharmaceutically-active bases used as vasoconstrictors, bronchodilators, antihistaminics, antibiotics, bactericidals, anaesthetics, sedatives and the like. The salts formed from the bases of this lastmentioned class and mercapto-alkane-sulfonic acids are now compounds which, at one and the same time, possess the pharmacological properties inherent in the organic base and the high mucolytic activity provided by the mercaptoalkane-sulfonic acid. Thus, Z-(p-aminobenzenesulfonamido) -thiazo1e mono-Z-mercaptoethane-sulfonate has the same bacteriostatic activity on gram-negative and gram-positive bacteria as sulfathiazole. Likewise, the administration of equimolecular quantities of each of hydroxyzine and 1 p chlorobenzhydryl-4-[2-(2-hydroxyethoxy)-ethyl] -piperazine mono 2 mercaptoethane-sulfonate neutralizes the same number of toxic doses of histamine. The medical interest of such compounds is obvious because it permits the accurately measured administration of medicines, the action of which is reinforced by the presence of the mercaptoalkane-sulfonic acids.

The following compounds are examples of new salts according to the present invention.

2-aminopyrimidine mono-2-mercaptoethane-sulfonate;

toxicity LD 50 (intravenously in the rat): 4 g./Kg. (by way of comparison, the LD 50 of N-acetyl-cysteine is 2.6 g./kg.);

ethylenediamine bis- (Z-mercaptoethane-sulfonate) 1-phenyl-2- N-methylamino) -propanol Z-mercaptoethane-sulfonate;

p-aminobenzene-sulfonamide mono-2-mercaptoethanesulfonate;

l-p-chlorobenzhydryl-4- [2- 2-hydroxyethoxy) -ethyl] piperazine mono-2-mercaptoethane-sulfonate;

Z-aminopyridine mono-2-mercaptoethane-sulfonate;

morpholine 2-mercaptoethane-sulfonate;

2-(p-aminobenzene-sulfonamido)-thiazole mono- 2-mercaptoethane-sulfonate;

2- 5, 6,7, S-tetrahydrol-naphthyl-methyl) -2-imidazoline Z-mercaptoethane-sulfonate;

2,4-diamino-5- (p-methyl-benzyl -pyrimidine mono- 2-mercaptoethane-sulfonate;

2-aminopyrimidine mono-3-rnercaptopropane-sulfonate;

guanidine mono-2-mercaptopropane-sulfonate;

2-aminopyrimidine mono-2-mercaptopropane-sulfonate;

guanidine mono-3-mercapto-Z-methyl-propane-sulfonate;

piperazine bis- Z-mercaptoethane-sulfonate) codeine 2-mercaptoethane-sulfonate;

1-methyl-3-morpholino-propyl 4-phenyl-tetrahydropyran- 4-carboxylate Z-mercaptoethane-sulfonate;

l-phenyl-4-(2,3-dihydroxypropyl) -piperazine mono 2-mercaptoethane-sulfonate;

2- Z-diethylamino-ethoxy) -ethyl l-phenyl-cyclopentanel-carboxylate 2-mercaptoethane-sulfonate.

The compounds according to the present invention are prepared by the conventional methods for preparing salts, preferably in aqueous solution, either by reacting a mercapt0alkane-sulfonic acid with a given inorganic or organic base, or by reacting an alkali metal or ammonium salt of a mercaptoalkane-sulfonic acid with a hydrohalogenide of a suitable organic base, or yet by double decomposition of a weak base salt of a mercaptoalkanesulfonic acid with a hydrohalogenide of a given inorganic or organic base. Other methods may also be used. The salts obtained are preferably purified by recrystallization from suitable solvents or mixtures of solvents.

The compounds according to the present invention are administered in a manner depending on the kind of mucus to be fiuidified. Thus, if they are meant for the treatment of the respiratory tract, administration in the form of aerosol is one of the preferred manners and the one best indicated in the majority of cases. For this reason, the compounds according to the present invention are advantageously presented in the form of aqueous solutions for aerosolization. Another equally possible form is the use of a micronized suspension in an inert propellant such as the Freons.

The preparation of aqueous solutions to be aerosolized is remarkably simple, because it is suflicient to dissolve, in degasified water, definite quantities of the salts according to the present invention and optionally of other water soluble pharmaceutically active compounds. Pharmaceutically acceptable stabilizing and Wetting agents may advantageously be added. If one or more of the pharmaceutically-active substances is not basic and is insoluble in water, stable emulsions can very easily be obtained by using conventional, pharmaceutically-acceptable emulsifiers. It is also possible to effect complete neutralisation of an aqueoussolution of mercaptoalkane-sulfonic acids with pharmaceutically-active bases, or partial neutralisation with said bases, followed by complete neutralisation with pharmaceutically-inactive inorganic or organic bases.

The thus obtained aqueous solutions or emulsions are preferably used in an aerosolizer operating under gas pressure; the propelling gas thus used is preferably inert, for example, nitrogen. During the treatment, the aerosol liberated is absorbed by the patient through the nose and is very elfectively distributed along the trachea so as to reach the less accessible parts of the bronchi.

The administration of the compounds or compositions according to the present invention is thus preferably done through the nose or by inhalation in the form of aqueous solutions, suspensions or emulsions, but they may also be administered per os in the form of syrups, solutions, drops, capsules, tablets, pills and the like or even by way of parenteral or rectal administration in the pharmaceutically known forms of aqueous or oily solutions, suspensions or emulsions or suppositoria. These various pharmaceutical forms are prepared according to methods currently used by pharmacists.

The to be administered dose of mucolytic agents according to the present invention varies within wide limits depending on the mode of administration. Since the agents are substances of low toxicity, the upper dosage limit depends on the tolerance of the mucous membranes rather than on the toxicity of these agents. Clinical tests have shown that the upper limit of concentration of such solutions of emulsions reaches 30%, solutions or emulsions containing up to 20-25% of mucolytic agent being generally well tolerated. Thus, when the mucolytic agent is administered in the form of aerosol, the quantity of mucolytic agent may reach 1 g. per application, and such an application may be repeated several times a day. For nasal instillations the best tolerated concentration in mucolytic agent varies from 2 to 5% for adults and is about 1% for children.

In order to determine the mucolytic power of the compounds according to the present invention, use has been made of the technique described by Sheffner (Annals of the New York Academy of Science, 106 (1963), art. 2, p. 298). By this method, the degree of fluidization of a 2.5% solution of the gastric mucus of the pig is determined by viscosimetry after 30 minutes incubation at 37 C. in the presence of the mucolytic agent to be tested (pH 8).

The results are given as a fluidization index, which corresponds to the diiference between the relative viscosities at zero time (V) and after 30 minutes (VI), expressed as a percentage of the initial relative viscosity:

X =Percent of fluidization The standard taken is the mucolytic activity of l.cysteine, to which the value of 100% is given, and the mucolytic activities of the compounds of the present invention are expressed in relation to those of l.cysteine. The results obtained are shown in the following table:

Furthermore, the mucolytic activity of the products according to the present invention has been studied making use of the fact that this activity brings about a breaking up of the water-insoluble molecular aggregates into molecular fragments that are soluble in water.

The determination of the dry weight of the water-soluble fraction, after centrifugation at high speed, is used to evaluate the mucolytic activity on human bronchial mucus.

TESTS IN VITRO When applied to tests on pathologic bronchial expectorations, the aforesaid method enables to study the characteristics of the activity of the salts of the mercaptoalkane-sulfonic acids according to the present invention and to compare them with other mucolytic agents. For example:

The total dry weight of the water-soluble constituents. of 1 g. human expectoration (chronic bronchitis) increases by 54% when this mucus is treated for 30 minutes at 37 C. with 1.64 mg. of sodium 2-mercaptoethane-sulfonate.

An increase of 68% is observed after a treatment with 3.28 mg. of the same salt under the same conditions.

The same biologic sample is treated under the same conditions with equivalent molar quantities of N-acetyll-cysteine. The water-soluble fraction is increased by 32 and 42% respectively..

CLINIC TESTS A marked mucolytic activity is observed in tests by aerosolization under pressure of 6 ml. of a 10% aqueous solution of 2-aminopyrimidine mono-2-mercaptoethanesulfonate.

By Way of comparison, a saline solution (placebo) has been administered to the same patients under the same experimental conditions.

The table herebelow is an example that shows results of treatment of 3 patients (chronic bronchitis). The figures correspond to percentages by weight of dry matter of the water-soluble fraction of mucus compared with the weight of dry matter of the total amount of the expectoration.

A sample of expectoration is collected before aerosolization and is used as control sample (sample 1).

The aerosolization lasts about 30' minutes. A second sample is collected in the course of treatment, 15 minutes after beginning (sample 2) and another immediately after ceasing the aerosolization (sample 3).

'1 hour and respectively 2 hours later, two further samples are collected (samples 4 and 5).

As mucolytic agent according to the present invention, use is made, in the tests, of 2-aminopyrimidine mono-2- mercaptoethanesulfonate (Aerosol A) in comparison with an aerosol of placebo (Aerosol B).

The results are given in the following table:

Sample N o.

Aerosol A Patient 1 Patient 2 Patient 3 Aerosol B This stability has been estimated under different conditions of temperature and treatment by dosage of the SH groups in dependence upon time.

After exposure to air for 64 days at room temperature or at 37 C., Z-aminopyrimidine Z-mercaptoethane-sulfonate retained its theoretical content of SH groups (13.9%

In sealed ampoules in an atmosphere of nitrogen, at a concentration of 0.125 mol, an aqueous solution of this compound retained its theoretical content of SH groups after 32 days (at room temperature, at 37 C. and at 57 0).

Finally, these same solutions in sealed ampoules in an atmosphere of nitrogen and sterilised for .20 minutes in an autoclave at 120 C., still retained their theoretical content of SH groups for 19 days following the treatment.

Example 1 hereafter illustrates the preparation of several therapeutic salts according to the present invention, Whereas Examples 2 to 11 illustrate therapeutic compositions having a mucolytic activity according to the present invention. It is, however, obvious that these examples do not limit the bearing of the present invention.

EXAMPLE 1 (a) Preparation of 1-phenyl-2-(N-methylamino)- propanol 2mercaptoethane-sulfonate 0.1 mol l-phenyl-2-(N-methylamino)-propanol dissolved in ethanol is added to a 30% aqueous solution containing 0.1 mol Z-mercaptoethane-sulfonic acid. The mixture is evaporated to dryness and the residue recrystallized from an isopropanol-aoetone mixture. Melting point of the obtained salt: 168169 C.

(b) Preparation of 2-aminopyrimidine mono-2- mercaptoethane-sulfonate 0.1 mol 2-aminopyrimidine hydrochloride dissolved in a minimum of hot Water is added to a 50% aqueous solution containing 0.1 mol guanidine mono-Z-mercaptoethane-sulfonate. The obtained solution crystallizes out after a few minutes. Melting point of the obtained salt: 174 C.

(c) Preparation of ethylenediamine bis (2mercaptoethane-sulfonate) The method of Example 1 is followed but 0.2 mol 2 mercaptoethane-sulfonic acid is used per 0.1 mol ethylenediamine. The otained salt is recrystallized from ethanol. Melting point of the salt: 320 C.

(d) Preparation of p-aminobenzene-sulfonamide mono-2- mercapto-ethane-sulfonate An aqueous solution of 0.1 mol p-aminobenzene-sulfonamide hydrochloride is added to an aqueous solution of 0.1 mol sodium Z-mercaptoethane-sulfonate. The obtained crystals are recrystallized from water. Melting point of the obtained salt: 235 C.

The same result is obtained using ammonium 2-mercaptoethane-sulfonate instead of the sodium salt.

(e) Preparation of 1-p-chlorobenzhydryl-4-[2-(2-hydroxyethoxy) ethyl] piperazine mono-Z-mercaptoethanesulfonate An aqueous solution of 0.1 mol Z-mercaptoethane-sulfonic acid is added to a solution of 0.11 mol l-p-chlorobenzhydryl-4-[2-(2-hydroxyethoxy)ethyl] piperazine in ethyl alcohol. The mixture is evaporated to dryness and the residue taken up in Water. This solution is extracted with diethyl ether to eliminate the excess base and then evaporated to dryness. A clear water-soluble resin is obtained.

Analysis. Calculated for C21H27C1N202'C2Hfi0382 percinst): N, 5.42; S, 12.38. Found (percent): N, 5.50;

7 The following salts were prepared according to one or the other of the above-mentioned methods:

2-aminopyridine mono-2-mercaptoethane-sulfonate: M.P.

80 C. (isopropanol);

morpholine 2-mercaptoethane-sulfonate: M.P. 95 C. (isopropanol);

2 (p-aminobenzene-sulfonamido)thiazole mono-Z-mercaptoethane-sulfonate: M.P. 205 C. (water);

2- 5,6,7,8-tetrahydrol-naphthyl-methyl) -2-imidazoline mono-2-mercaptoethane-sulfonate: M.P. 116 C. (isopropanolethyl acetate);

2,4-diamino-5-(p-methyl-benzyl) -pyrimidine mono-2- mercaptoethane-sulfonate: M.P. 176 C. (isopropanol);

Z-amino-pyrimidine rnono-3-mercaptopropane-sulfonate:

M.P. 160 C. water);

guanidine mono-2-mercaptopropane-sulfonate: M.P. 132

2-aminopyrimidine mono-2-mercaptopropane-sulfonate:

M.P. 141 C.;

guanidine mono-3-mercapto-2-methyl-propane-sulfonate:

M.P. 166 C.;

piperazine bis-(2-rnercaptoethane-sulfonate)z M.P.

codeine Z-mercaptoethane-sulfonate: uncrystallizable oil;

1-methyl-3-morpholino-propyl 4-phenyl-tetrahydropyran-4-carboxylate 2-mercaptoethane-sulfonate: uncrystallizable oil;

1-phenyl-4-(2,3-dihydroxypropyl)-piperazine mono-2- mercaptoethane-sulfonate: uncrystallizable oil;

2- 2-diethylamino-ethoxy -ethyl l-phenyl-cyclopentane- 1- carboxylate 2-mercaptoethane-sulfonate: 'uncrystallizable oil.

EXAMPLE 2 An aqueous solution meant for the treatment of the respiratory tract by inhalation has the following composition:

G. Sodium 2-mercaptoethane-sulfonate Phenylephrine hydrochloride 0.5 Tenaphtoxaline 0.1 Distilled water to 100 ml.

EXAMPLE 3 The following solution is used for aerosolization of the bronchi:

G. Sodium Z-mercaptoethane-sulfonate 5 94 ethyl alcohol l0 Distilled water to 100 ml.

EXAMPLE 4 The following solution is used for ear rinsing:

G. Sodium 2-mercaptoethane-sulfonate 5 Cetyltrimethylammoniurn bromide 1 Distilled Water to 100 ml.

EXAMPLE 5 The following solution is meant for intratracheal instillations or for nebulization:

G. Sodium '2-mercaptoethane-sulfonate 20 Ethylenediamine-tetracetic acid 0.5

Distilled Water to 100 ml.

In the four preceding examples, the pH of the solutions is adjusted to 7-8 by addition of a suitable quantity of sodium hydroxide. A bactericide may also be added to these solutions, e.g. a mixture of proply and methyl phydroxybenzoates.

EXAMPLE 6 The following powder is to be dissolved in distilled water when used and is meant as nasal drops:

Sodium 2-mercaptoethane-sulfonate 5 Neomycin (in the form of its sulfate) 1 EXAMPLE 7 For application by micronization, a 1% by weight suspension is prepared of sodium Z-mercaptoethane-sulfonate in a mixture of fluorinated hydrocarbons (l/ 1 mixture of Freon l1 and Freon 12).

EXAMPLE 8 A vasoconstrictive mucolytic preparation for nasal use contains the following:

Sodium 2-mercaptoethane-sulfonate g 5 2- 5,6,7, 8-tetrahydrol-naphthyl-methyl) -2-imidazoline 2-mercaptoethane-sulfonate mg 0.25 Distilled water to ml.

EXAMPLE 9 An antihistaminic mucolytic preparation for nasal use contains the following:

G. Sodium 2-mercaptoethane-sulfonate 1 5 1-p-chlorobenzhydryl-4-[2-(2-hydroxyethoxy)- ethylJ-piperazine mono-2-mercaptoethanesulfonate 0.25

Distilled water 100 ml.

EXAMPLE 10 A vasoconstrictive mucolytic preparation for nasal use contains the following:

Sodium 2-mercaptoethane-sulfonate 5 1-phenyl-2-(N-methylarnino)-propanol Z-mercapto-ethane-sulfonate 1 Distilled water to 100 ml.

EXAMPLE 1.1

A vasoconstrictive mucolytic preparation for nasal use contains the following:

Sodium Z-mercaptoethane-sulfonate 5 1-phenyl-2- N-methylamino -propanol Z-mercaptoethane-sulfonate 1 Neomycin -(in the form of its sulfate) 1 Distilled water to 100 ml.

What I claim is:

1. A mucolytic process which comprises contacting mucus in humans with a mucolytically effective amount of a pharmaceutically acceptable salt of a mercaptoalkane-sulfonic acid of the formula HSXSO H wherein X is an alkylene radical having from '2 to 6 carbon atoms.

2. A process according to claim 1 wherein the mercaptoalkane-sulfonic acid is used in amounts up to 1 gram.

3. A process according to claim 1, wherein the salt is sodium Z-mercapto-ethane-sulfonate.

4. A process according to claim 1, wherein the mercaptoalkane-sulfonic acid salt is administered in the form of an aqueous solution.

5. A process according to claim 1, wherein the mercaptoalkane-sulfonic acid salt is administered in the form of an aerosol.

References Cited UNITED STATES PATENTS 2,694,723 11/1954 Schramm et a1. 260-455 2,695,310 11/1954 Schramm et a1 260455 STANLEY J. FRIEDMAN, Primary Examiner U.S. Cl. X.R. 

